What is the frequency of such a wave?

Question

Near the shore, Tsunamis travel at a speed of 30 mph and the distance between crests is about 6.5 miles. What is the frequency of such a wave? Give your answer in units of Hz. When one crest hits the shore, how much time will pass before the next one makes it to shore

Answer 1

Period (T), frequency (f), speed (v) and wavelength (usually λ) are related by the equations

v = λ f

f = v / λ

T = 1 / f = λ / v

 

You're given a speed v = 30 mph and wavelength λ = 6.5 mi. You can use the 2nd and 3rd equations above to solve for f and T.